The invention relates to an apparatus for positioning a specimen by rotation about each of three axes.
Ultra-high vacuum vessels in which a specimen inside the vessel is to be moved externally make use of rotary or translational transmission ducts to transmit the motion to the specimen. While translational transmission ducts can be led relatively easily through the wall of the vessel using a bellows, rotary transmission ducts are very difficult to engineer. For this reason it is desirable to minimize the number of rotary transmission ducts required. There are occasions where a specimen in high-vacuum has to be moved through six degrees of freedom, i.e. said specimen must be rotational about each of three axes running at right angles to one another and in addition it must be capable of being displaced along the three axes. The invention deals specifically with the problem of rotating a specimen about each of three axes that are at right angles to each other.
The problem underlying the invention is to provide an apparatus of the type stated intially that permits a specimen to rotate about each of three axes by movement of a single shaft.